Dielectric Assessment of 11 kV Three-Core XLPE Power Cable during New Substation Commissioning

Assessing the condition of power cables is crucial to ensure they are ready for operation. Neglecting this can lead to significant losses, especially for large industrial users. A key indicator of potential issues is any discrepancy between the dielectric properties measured during commissioning and those specified by the manufacturer, which may suggest that the cables are not yet ready to be installed. To mitigate such risks, the dielectric performance of newly installed 3C 500MMP XLPE cables was evaluated both before and after jointing and termination, prior to commissioning the new main substation. The assessment included Insulation Resistance (IR) and Dielectric Absorption Ratio (DAR) tests, along with continuity and a 24-hour soaking test to verify electrical connectivity and overall performance. The IR and DAR tests yielded results within acceptable ranges, with insulation resistance values exceeding 0.1 GΩ and DAR values above 1.6. Continuity tests confirmed proper jointing and termination, as evidenced by resistance values below 5 Ω. Furthermore, the absence of tripping incidents during the 24-hour soaking period provided additional assurance of the cables’ readiness for energization.